U.S. considers attacking Islamic State militants in Syria

American journalist Steven Sotloff, center with black helmet, talks to Libyan rebels near Misurata in June 2011. Islamic State rebels who took him hostage have threatened to kill him.

American journalist Steven Sotloff, center with black helmet, talks to Libyan rebels near Misurata in June 2011. Islamic State rebels who took him hostage have threatened to kill him. (Etienne de Malglaive / Getty Images)

Declaring that the beheading of an American journalist was a terrorist attack on the United States, the Obama administration said Friday that it was weighing how to confront Islamic State militants in Syria, in what would be a major escalation of U.S. efforts to defeat the extremists.

President Obama, who sought to build a legacy as a leader who ends wars rather than starts them, until now had resisted direct U.S. intervention in the more than 3-year-old Syrian civil war.

But he has reconsidered his position as Islamic State forces have grown stronger and issued threats against Americans, most recently in a video this week showing the killing of American journalist James Foley at the hands of a masked executioner who spoke with a British accent. That has heightened concern that hundreds of militants have passports that could allow them to easily travel to the U.S., Europe and elsewhere.

Infuriated by Foley's grisly death, Obama is considering all options that might protect Americans from a threat that could reach the United States and other Western nations, a top advisor said, insisting that the president wouldn't be "restricted by borders."

"If you come after Americans, we're going to come after you wherever you are," said Ben Rhodes, deputy national security advisor. "And that's what's going to guide our planning in the days to come."

If you come after Americans, we're going to come after you wherever you are. And that's what's going to guide our planning in the days to come.— Ben Rhodes, deputy national security advisor.

So far, the U.S. air campaign against Islamic State has been contained to Iraq, where the group's stunningly fast takeover of a large swath of the country's north and west led Obama to order more than 90 airstrikes this month, reviving the American military presence in Iraq.

If Obama targets the militants in Syria, he'll be doing so in response to a direct threat to Americans, Rhodes said.

"The brutal execution of Jim Foley represented an affront," he said. "We see that as an attack on our country when one of our own is killed like that."

Over the last year, Islamic State militants have grown in capability, helped by money from criminal activity, donations and ransoms, as well as by the sanctuary of territory they have captured in Syria, said Pentagon spokesman Rear Adm. John Kirby.

Though Kirby stopped short of saying there were any plans to attack the militants in Syria, he said that "all options remain available."

The option of striking in Syria has been discussed in recent weeks between White House and Pentagon officials as they considered possible military actions against the group, a senior U.S. official said.

The White House is not eager to broaden the conflict into Syria, the official said, but wants to "let people know that [this reluctance] isn't necessarily going to keep us from striking, if necessary," the official said, speaking on condition of anonymity to discuss internal deliberations.

As part of the current operation in Iraq, the U.S. military said, it carried out three airstrikes Friday that destroyed two of the militants' armed vehicles and a machine gun nest that was firing on Iraqi forces.

The administration has described its effort in Iraq as both a humanitarian mission and a bid to protect Americans. To broaden the operation to include airstrikes in Syria, Pentagon lawyers are examining sources of authority that Obama could invoke, including the inherent right of self-defense against a group that has publicly threatened to attack the United States, the senior U.S. official said.

"Can the lawyers get to a solution? Probably," the official said.

The president also would have to decide whether to ask Congress for authorization or proceed without it, and probably would need to address whether the U.S. would take on the militants alone or build an international coalition. Obama is scheduled to attend a NATO summit next month in Wales.

If a decision is made to expand the air campaign in Syria, the White House prefers to have other countries involved militarily, but that might not be possible, the senior U.S. official said.

Bombing extremists' training camps and equipment in Syria could degrade their power and lessen the threat they pose in Iraq, the official said, but the gains would probably be temporary unless the U.S. continued bombing indefinitely. It would also extend U.S. military involvement in yet another chaotic, war-ridden country, one that Obama has sought for years to avoid.

Expanding U.S. airstrikes into Syria would present special challenges. With no ground presence there, the Pentagon might find it difficult to identify appropriate targets. That would especially be the case since administration officials have strictly ruled out any coordination with Syrian President Bashar Assad, whose government has fought Islamic State and other rebels, some backed by the U.S.

Syria's civil war that has killed more than 190,000 people and displaced more than 6 million, according to United Nations estimates.

Last summer, Assad's forces were accused of using poison gas against civilians, killing more than 1,000 people. That attack touched off fierce debate in Congress and a political predicament for Obama, who threatened to launch airstrikes but backed down when Assad agreed to surrender his chemical weapons to avoid such an attack.

Rep. William M. "Mac" Thornberry (R-Texas) criticized the administration's "slow rolling" about involvement in Syria's civil war, saying it has enabled the militants to "grow and expand" into Iraq.

"The first thing we should do is quit talking about what we're not going to do," Thornberry, vice chairman of the House Armed Services Committee, told CNN. "When the president takes options off the table, that only simplifies the planning of ISIS," he said, using an alternative acronym for the militant group.

U.S. intelligence proved faulty in Syria last month when a special forces team sought to rescue Foley and other captives held by Islamic State.

The hostages weren't at the site, and the group claimed responsibility for beheading Foley this week. It has threatened to execute another American captive, Steven Joel Sotloff, and are believed to be holding at least three other Americans.

Despite these challenges, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said Thursday that Islamic State fighters couldn't be defeated unless they were confronted in Syria, although he did not spell out what needed to be done.

One option for attacking in Syria would be to use covert drone strikes, which Obama has turned to in Pakistan, Yemen and other countries where extremists have established bases.

U.S. intelligence officials have warned the White House that Islamic State has a strong base in Syria and that bombing its positions in neighboring Iraq can go only so far in diminishing the militants' ability to regroup and launch counterattacks.

There is a "cross-border safe haven" in Syria, said a U.S. intelligence official. The militants control a large piece of territory stretching from Aleppo in the northwest to the border crossing with Iraq at Al Qaim in eastern Syria, he said.

The Iraqi government can "make progress" against Islamic State militants, but "it is a lot easier if the safe haven can be eliminated," he said, speaking on condition of anonymity to discuss internal assessments.

The official was not optimistic that the U.S. could do much to uproot the militants from Syria. "That safe haven will be there for a long time," he said.

Parsons reported from Edgartown and Cloud and Bennett from Washington. W.J. Hennigan in Washington contributed to this report.